Lester had rejected the four-year, $70 million offer made by the Red Sox in mid-March, then rejected the team's overtures to reopen negotiations during the season.

The Red Sox traded Lester at the July 31 deadline to the Oakland Athletics for outfielder Yoenis Cespedes. Lester and the Red Sox have always said a return to Boston is possible. Lester began his MLB career with Boston in 2006 and helped the team win two World Series titles in 2007 and 2013.

Lester, who turns 31 in January, is reportedly expected to command a contract for at least six years in the $130 million to $150 million range. Lester made $13 million last season.

Lester went 16-11 with a 2.46 ERA with 220 strikeouts last season for Boston and Oakland. In eight MLB seasons, he has compiled a 116-67 record with a 3.58 ERA with 1,457 strikeouts.